As is well known, only larger LED display screen can meet the requirements of people in some special place. In this case, all larger LED display screen are assembled by plurality of LED modules. In fact, the plurality of LED modules are fixed on the whole frame of the LED display screen respectively to form a larger LED display screen by assembling plurality of LED modules, and conventional LED modules are fixed by fixed connecting members such as screws. In such manner, the later maintenance and the replacing of the modules will be difficult. In addition, with the improving requirements of the resolving power of LED, the spacing of light source arranged on the LED modules is smaller and smaller, so the small spacing LED modules have no space for arrangement of the connecting members, such as screws. Conventional structure and design do not adapt to the producing of small spacing LED display screen, and this if the disadvantage of the conventional technology.